Problem: Simplify the following expression: $p = \dfrac{3x}{3x - 10} - \dfrac{2x - 10}{3x - 10}$
Answer: Since the expressions have the same denominator we simply subtract the numerators: $p = \dfrac{3x - (2x - 10)}{3x - 10}$ Distribute the negative sign: $p = \dfrac{3x - 2x + 10}{3x - 10}$ Combine like terms: $p = \dfrac{x + 10}{3x - 10}$